Storage container for cellulosic pulp and method of operation thereof



Jan- 1965 J. c. F. c. RICHTER STORAGE CONTAINER FOR CELLULQSIUPULP ANDMETHOD OF OPERATION THEREOF 2 Sheets-Sheet 1 Filed April 1, 1963 Jan.19, 1965 J. c. F. c. RICHTER 3,166,300

STORAGE CONTAINER FOR CELLULOSIC PULP AND METHOD OF OPERATION THEREOFFiled April 1, 1963 2 Sheets-Sheet 2 INV EN TOR ATTORNEYS United StatesPatent Oflice 3,166,300 STORAGE CONTAINER FOR CELLULOSIC PULP AND METHODOF OPERATION THEREOF Johan C. F. C. Richter, St. Jean Cap Ferrat,France, assignor to Aktieholaget Kamyr, Karlstad, Sweden, a company ofSweden Filed Apr. 1, 1963, Ser. No. 269,246

Claims priority, application Sweden, Apr. 16, 1962,

11 Claims. (Cl. 259-4) For storage of dense cellulosic pulp having a drycontent of 12 to 20 percent it is common to use bins or towers which arefilled from above and emptied at their bottom by flushing the pulp out.Flush water of a high pressure must be used which involves a high powerconsumption.

On the other hand, for mixing and equalization of pulp it is known touse circulation bins for pulp having a consistency of 3 to 4 percent. Ifsuch bins are to be used simultaneously for storage and mixing, theywill be very extensive and costly and yet of merely a modest capacity onaccount of the low consistency of the pulp.

The present invention relates to a container suitable for storage aswell as mixing of dense pulp, and also to a method of operating saidstorage container whereby an effective mixture and equalization of thepulp filling is obtained.

The essential feature of the method consists therein that the pulp, whencharged, is spread over the container so that it is stored therein insuperimposed horizontal layers, each of which extends at least over thegreater part of the horizontal area of the container and contains pulpsupplied approximately simultaneously, layers of various levels thuscontaining pulp supplied at different moments, and in that the pulp isdischarged from the container by a vertical or inclined movementextending over the entire height of the pulp filling, so that pulp ofthe various horizontal layers is mixed into the discharged pulp. Whenthe pulp is discharged by being flushed out with water, the water jetsare directed vertically or obliquely downwardly in such a manner thatthe water works simultaneously or with short intervals against thevarious horizontal pulp layers and at an inclined free front thereof.The pulp mixture thus formed is flushed through bottom outlets out ofthe container. In order to spread the pulp across the container whensupplied thereto there is used a charging device preferably arrangedabove the container and driven with a continuous uni-directional orreciprocating horizontal movement in such a manner that an orifice orsimilar thereon successively sweeps over the container in orderuniformly to distribute the fed pulp over the area of the container, themovement being so rapid and so often repeated that at any spot thefilling will be built up of a considerable number of superimposed thinlayers, eg to 50 layers. The flushing-out of the pulp which preferablyis performed by using flush water of a pressure of 25 to 50 lbs. per sq.inch, is preferably effected by a flushing device comprising a pipehaving one or more oscillating nozzles which are moved in parallel tothemselves or are swung in a horizontal plane in a movement independentof the movement of the abovementioned feeding device, possible onaccount of the flushing device being located in another horizontal planethan the feeding device.

The storage container according to the invention, in which theabove-mentioned method of charging and discharging pulp can bepractised, is essentially characterized by the provision of a chargingdevice which is horizontally movable above the container for spreadingof supplied pulp over the entire cross-sectional area of the containeras thin horizontal layers, and by the provision of a device forflushing-out pulp which is likewise arranged above the container inorder to be able simultaneously to flush pulp emanating from the variouslayers out through bottom outlets of the container, said flushing devicebeing horizontally movable independently of the feeding device.

The invention will be more closely described herein below with referenceto the accompanying drawing in which FIG. 1 shows a verticalcross-section of a preferred embodiment of the container, FIG. 2 shows aplan view thereof, and FIG. 3 shows a vertical cross-section taken alongthe cylindrical face indicated by the line I-I in FIG. 2.

The container shown in the drawing consists of an upright cylindricalouter Wall 11, and a plane horizontal bottom 13. By means of aconcentric inner wall 15 the container is divided into two separatecompartments preferably having equally great base areas. Distributedover the bottom of the two compartments are outlet openings 17 groupedin radial rows. Each row of openings 17 is partly covered by a low,radially directed wall 19 which projects from the bottom at an acuteangle. At least one of said walls of each compartment extends as apartition 21 (FIG. 3) up to the level of the upper edge of the walls 11,15. In the base below the bottom 13 there are arranged two concentriccollecting chambers 22, 23 which are provided with stirrers 25- andwhich, via conduits having shut-off valves 24 and 26, are alternatelyconnectible to a conduit 29 for pulp discharged from the container, inwhich conduit a pump 27 is inserted.

The dense pulp to be stored in the container is supplied by a bandconveyer 31 to a charging device comprising a conduit 33 arranged toswingin a horizontal plane above the container and which is pivoted on apillar 35 located at the center of the container, the outer end of saidconduit 33 being supported by a motor-driven carriage 37 running on theupper edge of the wall 11. Within the conduit there is a motor-drivenscrew conveyer 39 which takes care of pulp introduced into the conduitthrough a hopper 41 arranged at the inner end thereof and dischargessaid pulp through one or the other of two outlet openings 43, 45arranged on the lower side of the conduit. The inner opening 43 can becovered by a shutter 47 when the pulp is desired to pass to the outeropenings 45.

Located at a lower level than the above-described pulp charging devicebut yet above the container and pivotable in a horizontal plane is aflushing device comprising a horizontal flush water supply tube 51,attached to which are two nozzles 53, 55 which are pivotable in thevertical plane or in a steeply inclined plane, said plane beingessentially parallel to the partition 21 (FIG. 3) when the flush watertube 51 is located approximately straight above said partition. Theflush water tube 51 is pivoted on the central pillar 35 and is connectedto a supply tube 57 for water of a relatively moderate pressure, saidtube extending through the pillar. The outer end of the tube 51'issupported by a motor-driven carriage 59 which like the carriage 37 runson the upper edge of the wall 11 but inwardly of the path of saidlast-mentioned carriage, so that the two carriages can pass each otherunimpededly, the movement of the charging device thus being completelyindependent of the flushing device serving to discharge the pulp.

With respect of each of the compartments the charging device and theflushing device are active alternately, one being active when the otheris inactive, and vice versa. However, the provision of two compartmentsenables simultaneous continuous pulp feed and continuous pulp discharge,pulp being charged into one compartment dur ing intervals when pulp isdischarged from the other, as shown in FIG. 1.

When filling the container with pulp the conduit 33 Patented Jan. 19,1965 of the charging device is driven at such a speed that for eachrevolution merely a thin layer of pulp is laid off upon the earlierstored pulp. Thus the tube 33 must turn a great number of revolutions,eg to 50 revolu- I tions or more, in orderto fill up the containercompletely. herefore, in a vertical cross-section through the filledcontainer an equally great number of layers of different storing agescan be discerned.

The discharge of pulp out of the filledcompartment takes place by aflushing operation by means of the pivoting nozzles 53, 55 and startswith saidnozzles in a position above the partition 21, so that a flow ofdiluted pulp can find its way along said partition to the outlet 17wtihout the risk of pulp dropping down and obstructing the open passagethus formed. Each of thenozzles 53 the pulp along a free front thereofextending along the entire height of the pulp filling and will thereforecarry with it and mix pulp particles emanating from all the variouslayers. The flush water dilutes the pulp to a consistency of e.g.approximately 3 percent, and the suspension flows through the nextoutlet 1'7 down into the collecting chamber 22 from where it is pumpedfurther on. The outlets 17 may be permanently open, because stored pulpof a consistency of 12 to '20 percent is too solid to be able to passtherethrough by itself.

Within this scope of the invention modifications of the above-describedembodiment are possible in various respects. Thus for instance, thecontainer may be given a rectangular base area, the feeding device aswell as the flushing device then preferably being arranged for areciprocating rectilinear movement above the container.

I claim:

1. Method of storing and mixing cellulosic pulp in the pulp isdischarged from the container by flushing with at least one flush waterjet which is directed obliquely downwards in such a manner thatthelwater'ima container, consisting in spreading pulp supplied to thecontainer for storage therein by displacing the point of supply of pulphorizontally over the container at a rapid rate, whereby pulp suppliedwithin a short time interval is distributed over the entire bottom areaof the container as a thin horizontal sheet, forming a great number ofsuperimposed thin pulp layers by repeating said spreading operation, anddischarging pulp from said container by means of flush water brought tohow in an inclined downwardly directed path across the pulp chargethereby bringing along and mixing pulp particles belonging to all ofsaid layers into a suspension leaving the container.

2. In the storage of dense cellulosic pulp in and removal thereof from astorage container, a method for equalizing the properties of the pulpcomprising: charging a first layer of pulp into the container, spreadingsaid layer over at least the greater part of the horizontal area of thecontainer, subsequently charging and spreading a plurality ofsuperimposed horizontal layers of pulp onto said first layer one layerat a time so that each layer excepting the first layer contains pulpcharged and spread subsequent to the pulp in the layer immediately belowit; discharging the pulp from the container by serially re moving aplurality of inclined increments pulp from the container, each incrementextending over substantially the entire height of the first pulp layerand the pulp layers superimposed thereon so that each incrementdischarged contains pulp from each pulp layer.

3. Method as claimed in claim 2, characterized in that pingessimultaneously upon at least a majority of the horizontal layers of thepulp charge at a progressively moving point with respect to the layersso as to define an inclined free front thereof and flushes the pulpmixture thus formed out of the container.

4. Method as claimed in claim 2, characterized in that the pulp isspread from a moving pulp dispenser with generally horizontal movementin such a manner that the pulp dispenser successively sweeps overdilferent parts of the container in order evenly to distribute the fedpulp over the entire area of the container, and in that the movement isthat rapid and 'thatoften repeated that the charge will consist of 10to, 50 superimposed thin horizontal layers.

5. Method as claimed in claim 4, characterized in that the feeding stepand the flushing step are repeated alter-v natingly.

6. Method as claimed in claim 4 wherein the rate of sweep of said movingpulp dispenser is substantially greater than the rate progressingmovement of said flush water jet.

7. Storage container for cellulosic pulp comprising means definingcontainer sidewalls and a container bottom; means defining an outlet insaid bottom; a device for feeding pulp to the container, said devicecomprising av conduit having means defining at least one dispensingopening therein, said conduit being horizontallymovable above thecontainer in order to spread the pulp over the entire area of thecontainer in the shape of thin horizontal layers, and a device forflushing pulp out of the container, which device likewise is arrangedabove the container in. order to be able simultaneously to flush pulpemanating from the various layers out through said bottom outlet of thecontainer, said flushing device being horizontally movable independentlyof the feed device.

8'. Container as claimed in claim 7, characterized in that the containeris'cylindrical and that the feeding device and the flushing device arepivotable about an axis concentric to the container and arranged indifferent horizontal planes, so that they can move fully around and pasteach other without mutual interference.

9. Container as claimed in claim-7, characterized in that the flushingdevice comprises a horizontallymovable flush water supply pipe, to whichare attached a plurality of nozzles pivotable in steeply inclinedplanes.

10; Container as claimed in claim 8, characterized in that the containeris divided up by means of radially extending partitions which aresomewhat inclined to the vertical, bottom outlets being arranged in thebottom of the container close to each of said partitions and on the sidethereof forming an acute angle to the bottom.

11. Container as claimed in claim 8, characterized in that the containeris divided up by means of a cylindrical wall into an inner container andan outer annular container, andthat the feeding device and the flushingdevice are adapted for work alternatingl'y in the inner and the outercontainer.

References Cited by the Examiner UNITED STATES PATENTS 756,327 4/04Carkeek 209-498 923,571 6/09 Paterson 2594' 1,010,244 11/11 Fairfield210-221 CHARLES A. VVILLMUTH, Primary Examiner.

1. METHOD OF STORING AND MIXING CELLULOSIC PULP IN A CONTAINER,CONSISTING IN SPREADING PULP SUPPLIED TO THE CONTAINER FOR STORAGETHEREIN BY DISPLACING THE POINT OF SUPPLY OF PULP HORIZONTALLY OVER THECONTAINER AT A RAPID RATE, WHEREBY PULP SUPPLIED WITHIN A SHORT TIMEINTERVAL IS DISTRIBUTED OVER THE ENTIRE BOTTOM AREA OF THE CONTAINER ASA THIN HORIZONTAL SHEET, FORMING A GREAT NUMBER OF SUPERIMPOSED THINPULP LAYERS BY REPEATING SAID SPREADING OPERATION, AND DISCHARGING PULPFROM SAID CONTAINER BY MEANS OF FLUSH WATER BROUGHT TO FLOW IN ANINCLINED DOWNWARDLY DIRECTED PATH ACROSS THE PULP CHARGE THEREBYBRINGING ALONG AND MIXING PULP PARTICLES BELONGING TO ALL OF SAID LAYERSINTO A SUSPENSION LEAVING THE CONTAINER.